Improvement in the method and apparatus for photographing objects in motion



2 Sheets-Sheet 1.

E. J. MUYBRIDGE. Method and Apparatus for Photographing Objoots inMotion.

No. 212,865. Patented Mar. 4, 1879.

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Method and Apparatus for Photographing Objeots in Motion.

Patented Mar. 4,1879.

UNITED STATES PATENT OFFICE.

EDXVARD J. MUYBRIDGE, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT it! THE METHOD AND APPARATUS FOR PHOTOGRAPHiNG OBJECTS 1NMOTlON.

Specification forming part of Letters Patent No. 212,865, dated March 4,1879; application filed June 27, 1878.

To all whom it may concern:

Be it known that I, EDWARD LMUYBRIDGE, of the city and county of SanFrancisco,St-ate of California, have invented certain Improvements inTaking Instantaneous Photographs of Objects in Motion; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof, reference being had to certain drawings accompanying thisspecification, and forming-a part of the same.

My invention has reference to that branch of photography which is knownas instantaneous photography, and it applies more particularly where theobject to be photographed is in rapid motion.

The principal object which I have in view is to take photographic viewsof horses that are moving rapidly under speed, in order to determine theposture, position, and relation of their limbs in different portions oftheir step or stride.

Myinrention relates to a double-acting slide, with the means foroperating the same, and to a novel background, which is graduated ormarked so as to gage the position of the horse and the posture of hislimbs, all as hereinafter more fully described.

leferring to the accompanying drawings, Figure 1, Sheet 1, is aperspective; Fig. 2, Sheet 1, is an end section, showing cameraslides,track, and background. Fig. 1, Sheet 2, is a section of slide-frame,showing trigger, lever, armature, and magnets. Fig. 2, Sheet 2,represents a photograph. Eig. 5, Sheet 2, represents a contact-plate.

Let A represent the track along which the horse is made to pass underspeed. 011 one side of the track I place the photographic camera- Ii,the tube of which is directed across the roadway or track. Immediatelyin trout of the camera-tube I place the frame D, in which mydouble-acting slides c d are arranged. The two slides are mounted in theframe side by side,in parallel planes, so as to stand across the end oicamera-tube. Each slide has an opening, 0, in it, which will usually beas wide as the diameter of the cameratube, but in some instances I shallmake it less.

The slide 0 is connected by one or more springs, r, with the top of theframe I), while the slide d is similarly connected with the bottom ofthe frame, so that when the two slides are drawn to their respectiveinactive positions the solid portion of each slide is opposite theopenin in the adjoining slide, and a solid plate is presented in frontof the cameratube. To set these slides the upper one is drawn down andthe lower one is drawn up until the openings 6 pass each other and thesolid portions come opposite the openings again, thus straining thesprings r, in which position both slides are secured by a single lever,f, and trigger g. The lever f catches lightly upon the trigger g, andthe opposite end of the trigger is connected with a lever, G, which ispivoted at its middle to the outside of the frame, and the opposite endof which carries an armature, 71 I 1 are electromagnets, which areattached to the side of the frame under the armature. A wire, j, leadsfrom these magnets to the battery, which may be conveniently located,while another wire, 7:, leads across the track, either underground oroverhead, as hereinafter explained.

The background L is placed on the side oi the track or roadway oppositethat on which the camera and slide are located, so that the horse mustpass between them. I prefer to paint this background white, so thatthehorse will stand out in better relief and his position and posture bemore distinctly shown in the photograph. I also whiten the track betweenthe camera and background. Near the bottom of this background I paint orotherwise delineate several lines or stripes, Z I, at differentcalculated spaces apart, so that, the distance of the horses feet fromthe ground at the in stant the photograph is taken will be shown uponthe picture by the position of the feet with relation to the lines.

On the rear side oi. the background I secure two metallic spring-plates,m m, so that one will be slightly distant from the other. The wire j,which leads from. the magnets I, I attach to one of these plates, andthe other plate I connect by a wire with the battery. For a runninghorse I then attach one end of a strong thread, 0, to the outside plate,m,aud stretch it across the track at the proper height, so that thehorse will run against and break it as he passes. The strain upon thethread when the horse runs against it will draw the and release thetrigger. The instant the trigger is released the springs r draw theslides 0 cl in opposite directions, so that the sensitive plate in thecamera is instantaneously exposed as the openings 0 pass each other. Thecamerais so located with reference to the slides that it is directlyopposite the openings when they coincide with each other, sothat a fullexposure is had.

For a trotting horse I operate the outer spring-plate, m, to make theconnection with the under one by causing one of the wheels of the sulkyor vehicle to pass over the connection that draws the plates together.

In order to take several successive views I employ a number of camerasand slides in connection with a single background of the requiredlength. In this case I place the cameras at regular intervals apart andmake a separate circuit and operating device for each. I. also paint orotherwise mark the background with vertical lines 8 s at regularintervals apart, and number them successively by painting the numeralsupon them. These vertical lines will then show the position and progressof the horse and his posture at each exposure.

I am aware that a graduated background used in photography for thepurpose of ascertaining the velocity of a moving object in agiven timeis not new, and I do not, therefore,

desire to be understood as claiming such a background, broadly; but,

Having described my invention, what I do claim as new, and desire tosecure by Letters Patent, is-- 1. The background L, provided withvertical lines or gage-stripes s and horizontal stripes or lines 1,arranged substantially as shown and described, for the purpose ofobtaining horizontal and vertical measurements of the passing object, asset forth.

2. The slides a d, set by means of the lever f, trigger g, andcentrally-pivoted lever G, with its armature h, in combination with theelectro-magnets I I, wires j k, and metallic spring-plates m m,-constructed to operate substantially as and for the purpose described.

7 In witness whereof I have hereunto set my hand and seal.

E. J. MUYBRIDGE. 11.. s.]

